"Almost all aspects of life are engineered at the
molecular level, and without understanding molecules we can
only have a very sketchy understanding of life itself."

--Francis Crick

As a theorist in a science based on experiment, Francis
Crick, more than any other single scientist, defined the
field of molecular biology during its "classical period"
from the discovery of the double helical structure of
deoxyribonucleic acid (DNA) in 1953 to the elucidation of
the complete genetic code in 1966. In the words of fellow
Nobel laureate Jacques Monod, "No one man discovered or
created molecular biology. But one man dominates
intellectually the whole field, because he knows the most
and understands the most: Francis Crick." Crick went on
to make important contributions to developmental biology
and, during the last twenty-five years of his life, to
neurobiology. His insights into DNA and the genetic code,
ground-breaking in their time, have become standards of
science education as well as references in popular culture.

Francis Harry Compton Crick was born on June 8, 1916,
to middle-class parents in Northampton, England, a center
of leather and footwear manufacturing. Crick's father
managed a shoe and boot factory which his own father had
founded. His mother was a school teacher.

In his autobiography, What Mad Pursuit (1988), Crick
recounts that while a student at Northampton Grammar School
he performed chemistry experiments, including a failed
attempt to make artificial silk, but otherwise does "not
recall being exceptionally precocious." At age fourteen he
won a scholarship to Mill Hill School, a private boys'
school in North London. Crick remembers that science
instruction there was thorough, but still he learned the
basics of Mendelian genetics on his own because it was not
taught at the school.

Upon graduating from University College London in 1937
with a second-class honors degree in physics, he took up
graduate work in physics at the college, studying the
viscosity of water at high temperatures. These studies,
which never engaged Crick intellectually, were interrupted
by World War II when a bomb destroyed his apparatus.
During the war he served on the scientific staff of the
Admiralty, where he designed acoustic and magnetic mines
for naval warfare.

In 1947, Crick, thirty-one years old, intellectually
restless, weary of military research, and with an
undistinguished record in his chosen field of physics,
decided to change fields and careers altogether. In making
this decision he applied what he called the "gossip test":
he figured that the issues one feels most passionate for
are those one gossips about, and that insight will come
from the curiosity and dedication that only passion can
sustain. Crick thus determined that he was faced with a
choice between two scientific areas: molecular biology and
the mysteries of consciousness. Concluding that his
training in physics prepared him better for the former,
Crick in 1947 successfully applied for a fellowship from
the Medical Research Council (MRC), the agency that has
general responsibility for the promotion of biomedical
research in Britain.

Crick joined a cohort of physicists, including Max
Delbrück, Leo Szilard, Maurice Wilkins, and Seymor Benzer,
who turned to molecular biology in order to apply
approaches central to physics (quantum mechanics,
quantitative methods, and model building) to a science with
few theoretical or mathematical underpinnings. Crick
characterized the intellectual adjustment required by his
transition from physics to biology "almost as if one had to
be born again," because a theorist in biology
had to rely on experimental evidence to a much
greater extent than in physics. With little knowledge of
biology, Crick went to Cambridge University to work at the
Strangeways, a tissue culture laboratory where for two
years he studied the physical properties of cytoplasm, the
material of the cell that surrounds the nucleus, while
reading widely in biology and chemistry.

In 1949, he transferred to the MRC's unit at the
Cavendish physics laboratory in Cambridge. There he
pursued doctoral research under Max Perutz on the
determination of protein structure by X-ray
crystallography, a technique by which crystals of molecules
were exposed to X-rays, yielding a diffraction pattern on
photographic film which allowed inferences about the
position of the individual atoms within the molecule.

In the summer of 1951, Crick began his collaboration with
James D. Watson, a postdoctoral fellow from the United
States eleven years his junior. Their collaboration is the
best-known of several examples of Crick's remarkable
ability to form sustained productive friendships with other
scientists. During long conversations in their shared
office and at daily lunches at The Eagle, a pub around the
corner from the Cavendish, the two delineated the physical
structure of DNA, the molecule that had recently been shown
to control heredity. They reported in the journal Nature
on April 25, 1953, that DNA consisted of a double helix in
which two sugar-phosphate backbones were linked like a
twisted ladder by four types of nitrogen-containing bases,
so that adenine was always paired with thymine and guanine
with cytosine. The pairing rule meant that the two chains
were complementary and that each could serve as a template
for a new chain during cell division, providing a model for
the transmission of hereditary characteristics from one
generation to the next.

In recognition of their discovery Watson and Crick
received the Nobel Prize in Physiology or Medicine in 1962
together with Maurice Wilkins, the crystallographer who had
taken the first high-resolution X-ray images of DNA fibers
and who had thus laid the groundwork for their discovery.
Later Crick hung a helix, single-stranded and painted gold,
over the door to the double-wide row house in the historic
center of Cambridge he and his family occupied for many
years.

Crick regarded the discovery of the double helix as a
powerful example of the experimental and theoretical
methods by which complex problems in biology could be
reduced to fundamental laws of physics and chemistry.
Indeed, throughout his scientific career he was driven by
his conviction that the origins and processes of life,
including human consciousness and free will, could be
explained entirely in rational, scientific terms. In a
series of lectures published under the title Of Molecules
and Men (1966), he formulated his stance against what he
called vitalism, the belief that life, evolution, and
consciousness were generated and directed by a metaphysical
force not subject to verification by experiment. An avowed
atheist, Crick resigned as a fellow of Churchill College,
Cambridge, after one year when the college decided to erect
a chapel, which he considered an offensive anachronism.

Crick earned his PhD degree from Cambridge
University's Gonville and Caius College in 1953, with a
dissertation entitled "X-Ray Diffraction: Polypeptides and
Proteins," in which he worked out the theory of X-ray
diffraction by a helix. He spent the 1953-54 academic year
as a postdoctoral researcher in the laboratory of the X-ray
crystallographer David Harker at the Polytechnic Institute
of Brooklyn, the first of many visits to the United States.

Upon returning to the MRC laboratory at Cambridge, his
home institution for the next twenty-two years, Crick
undertook research of rare breadth. (He never taught or
advised students.) He renewed his collaboration with Watson
in 1955, when the two developed a general theory about the
molecular structure of small viruses, and he worked with
the visiting American biochemist Alexander Rich on the
structure of several biological molecules, particularly
collagen, a family of proteins that are found outside of
cells and that give strength and flexibility to connective
tissue.

However, Crick devoted most of his efforts between
1954 and the mid-1960s to studying the genetic coding
problem, that is, the action by which genes controlled the
synthesis of proteins, the building blocks of life. Crick
inferred that the sequence in which the four bases of DNA
were arrayed encoded the instructions for building long
chains made of a combination of the twenty common amino
acids, which then folded themselves up into proteins.
(Watson and Crick drew up the canonical list of twenty
amino acids at The Eagle.) Crick called this inference the
sequence hypothesis. The challenge was to decipher the
code by which the four-letter language of DNA was
translated into the twenty-letter language of proteins. In
tackling the coding problem, Crick assumed that genetic
information, once transmitted from DNA (probably through a
messenger made, most likely, of ribonucleic acid, or RNA)
and used to assemble the amino acid chain, could not
reversely flow out of the protein and affect the sequence
of the bases in the RNA messenger. This he proclaimed to
be the "Central Dogma" of molecular biology. Finally, he
predicted the existence of a group of molecules, later
found and called transfer RNA, that aided in the assembly
of the amino acid chain.

Crick began work on the genetic code with Vernon
Ingram and continued it during his most enduring
collaboration, that with the South African geneticist
Sydney Brenner, from 1957 onward. In 1961, Crick and
Brenner described in Nature how, by studying mutations in a
bacterial virus, they obtained evidence that the genetic
code was to be read three bases at a time, proceeding in
one direction from a fixed starting point on the DNA
strand. (The American biochemist Marshall Nirenberg had,
concurrently, reached the same conclusion.) Over the next
five years, Crick and his colleagues in England and the
United States identified the triplets for all twenty amino
acids in a rush of inspired research and friendly
competition.

With the elucidation of the genetic code completed and
molecular biology established on a firm footing, Crick in
the mid-1960s turned to other fields, especially to
developmental biology, the study of how genes control the
growth and specialization of organs. To reflect this shift
Crick and Brenner, who in 1962 had become joint heads of
the Molecular Genetics Division of the Medical Research
Council's newly-established Laboratory of Molecular Biology
in Cambridge, renamed the division the Division of Cell
Biology in 1969. During these years he was much in demand
as a lecturer, a role in which he excelled and in which he
traveled the globe.

In 1976, he began a sabbatical year at the Salk
Institute for Biological Studies in La Jolla, California, a
privately-funded research institute whose scientific
direction Crick, as a Visiting Fellow, had helped to plot
from the time it was built in 1962. In 1977, he accepted a
permanent appointment there as J. W. Kieckhefer Research
Professor. He used the occasion of his relocation to the
United States to shift his focus from molecular biology to
his other long-standing scientific interest, neurobiology.
In further collaborations, notably with the computational
neuroscientist Christof Koch, Crick studied the visual
system of humans in an attempt to uncover the neural
correlates of consciousness, how the electrochemical
interactions of nerve cells in the cerebral cortex and
related parts of the brain give rise to the subjective
mind. He explained his approach to consciousness in The
Astonishing Hypothesis: The Scientific Search for the Soul
(1994), and published articles on such issues as the
action of dendritic spines and the function of dream sleep.
He was editing his latest article on neurobiology just days
before his death from colon cancer on July 28, 2004, in La
Jolla, California, at age eighty-eight.

Crick was elected a Fellow of the Royal Society in
1959, became a Foreign Associate of the U.S. National
Academy of Sciences in 1968, and was a member of the French
Academy of Sciences and the Irish Academy of Sciences. He
received the Lasker Award, often called the American Nobel
Prize, in 1960, with Watson and Wilkins. He also received
the Award of Merit of the Gairdner Foundation of Canada,
and the Prix Charles Leopold Mayer of the French Academy of
Sciences, along with other important recognitions. In
1991, the Queen named Crick to the Order of Merit, an
honorary institution of 24 outstanding scientists, artists,
and writers. (Contrary to common assumption, he was never
knighted.) Crick is the author of four books and more than
130 scientific articles.

His first marriage, to Ruth Doreen Dodd, ended in
divorce in 1947. He was survived by his wife, Odile,
until her death on July 5, 2007, an artist whom he met
at the Admiralty while she was
serving as a translator of captured German documents, and
whom he married in 1949; a son from his first marriage,
Michael F. C. Crick of Seattle, a software designer in
Seattle; two daughters from his second marriage, Gabrielle
A. Crick and Jacqueline M. T. Nichols, both of England;
and six grandchildren.

1947 --Receives a Medical Research Council (MRC) fellowship to conduct research on the physical properties of cytoplasm at the Strangeways
tissue culture laboratory in Cambridge, England, under Arthur Hughes

1949 --Marries Odile Speed (d. 2007)

1949 --Transfers from the Strangeways to the MRC Unit for the Study of the Molecular Structure of Biological Systems at the Cavendish
laboratory in Cambridge in order to investigate protein structure under Max Perutz

1951 --Begins his collaboration with James D. Watson on the structure of deoxyribonucleic acid (DNA)

1953 --Watson and Crick describe their double-helical model of DNA in a two-page article in Nature (April 25)

1953 --Receives his PhD from Gonville and Caius College of Cambridge University with a thesis on "X-Ray Diffraction: Polypeptides
and Proteins"

1953-54 --Spends a postdoctoral year in the X-ray crystallographic laboratory of David Harker at Brooklyn Polytechnic Institute

1955 --Proposes a molecular structure for the protein collagen with Alexander Rich; collaborates with Watson on the structure of
small viruses; circulates "On Degenerate Templates and the Adaptor Hypothesis," an unpublished paper which predicts
the existence of transfer ribonucleic acid (tRNA)

1956 --Collaborates with Watson on the structure of small viruses

1957 --Proposes the "Sequence Hypothesis" and the "Central Dogma," path-breaking concepts about how genetic information
is encoded in DNA and controls protein synthesis

1959 --Elected a Fellow of the Royal Society

1960 --Receives the Albert and Mary Lasker Award with Watson and Maurice Wilkins

1961 --Crick and Sydney Brenner demonstrate that three nucleotides, a triplet, code for each amino acid during protein synthesis

1962 --Becomes joint head, with Brenner, of the Molecular Genetics Division (later the Division of Cell Biology) of the newly-founded
MRC Laboratory of Molecular Biology in Cambridge

1962 --Crick, Watson, and Wilkins share the Nobel Prize in Physiology or Medicine

1966 --Allocation of all 64 triplets of the genetic code is completed, which Crick declares a "historic occasion"

1966 --Publishes Of Molecules and Men, in which he argues against "vitalism," the belief in a metaphysical spirit
which animates all life

1976 --Takes a sabbatical at the Salk Institute for Biological Studies in La Jolla, California, to take up research in the neurobiology
of the visual system

1977 --Receives lifetime appointment as Kieckheffer Distinguished Research Professor at the Salk Institute; resigns from the MRC

1981 --Publishes Life Itself, a speculation on the possible extraterrestrial origins of life on earth